G.I. Joe: The Rise of Cobra filmed at Hrad Kost, Sobotka. Stands in for a French fortification in the 1664 prologue, where McCullen's ancestor is sealed inside a metal mask. On screen it's French fortification.
Probable Named in published production coverage; the coordinate is the place itself, checked against a gazetteer.
Planning the trip? The Czech Republic travel atlas covers money, language and getting around
Venture keeps every scene location on one map, sorted by how far you'd have to walk. Open it in Sobotka and it tells you what was shot around you, how to get there, and whether you can actually go in.
Download Venture for iOS Android